Crestor is the brand name of rosuvastatin calcium, one of a class of cholesterol-lowering drugs known as statins. These drugs reduce the production of harmful low-density lipoprotein (LDL) cholesterol in the liver by inhibiting the action of an enzyme known as HMG-CoA reductase. Among the approximately 13 million Americans who take statins, the most common side effect is musculoskeletal pain, notes the Arthritis Foundation. Use of any statin drug, including Crestor, may also involve more serious side effects on muscles.
Myalgia is the medical term for generalized muscle pain and tenderness. A general sense of unwellness or malaise may accompany those muscle symptoms. Myalgia ranks among the most common side effects of Crestor, as noted in the prescribing information for the drug at Drugs.com. The prescribing information, approved by the U.S. Food and Drug Administration, also documents increased rates of myalgia at higher doses of Crestor. It identifies myalgia as the most common reason for the cessation of treatment during the JUPITER clinical trial of 17,802 participants.
In a 2002 clinical advisory on the use and safety of statins Dr. Richard C. Pasternak and colleagues define myalgia as muscle discomfort without elevated levels of the enzyme creatine kinase in the blood, which indicates muscle breakdown. The muscle pain and tenderness experienced with myalgia may, however, signal more serious medical problems and people who take Crestor should inform their doctors of any muscle pain or tenderness, especially if they also experience fever or malaise.
Myopathy, or weakness and degradation of skeletal muscle tissue, may occur in those who take Crestor. The risk of developing myopathy increases when people take the highest dose. MedlinePlus notes that before taking Crestor people should notify their doctors if they use of any other cholesterol drugs including fenofibrate, clofibrate, niacin and genfibrozil. These drugs may increase the risk of myopathy if taken with Crestor. Predisposing factors for elevated risk of myopathy include renal impairment and hypothyroidism. People who are 65 or older might also run a higher risk of experiencing myopathy as an effect of taking Crestor. When people of Asian descent take Crestor, the peak plasma concentrations of the drug reach a higher level than in Caucasian people. This increased exposure carries an increased risk of side effects on muscles and the prescribing information recommends that doctors begin treatment with Crestor at the lowest dose in this population.
The University of Maryland Medical Center describes rhabdomyolysis as a disorder in which muscle cells break down and release myoglobin into the blood. The kidneys filter myoglobin from the blood, but the compounds produced when myoglobin breaks down cause damage to the kidneys. Doctors can confirm a diagnosis of rhabdomyolysis when levels of creatine kinase increase to over ten times the normal range. Rhabdomyolysis, if untreated, can lead to kidney failure and death. The prescribing information for Crestor emphasizes that the risks of rhabdomyolysis exists at all doses but increases at the highest does. The muscle symptoms include pain, weakness or tenderness and a visible sign is red or dark urine.